Bit



Patented Sept. 15, 1931 UNITED STATES JOHN W. MARTIN, F HUMBLE, TEXAS;

BIT

Application "filed. April 18,

The present inventionappertains to new and useful improvements in bits for well boring drills and more particularly the present invention provides a bit of the disc cutting type.

The primary object of the inventlon is to provide a bit which will cut with more case and efficiency than most types of bits now in general use.

After reading the following specificatlon and claims, other important objects and advantages of this invention will become apparent.

In the drawings:

Figure 1 represents a side elevation of the preferred form of the invention.

Figure 2 represents a longitudinal sectional view through the bit, taken substantially on the line 22 of Figure 1.

Figure 3 represents a fragmentary sectional view of a modified form of the present invention.

Referring to the drawings wherein like numerals designate like parts, it will be seen that the novel bit includes in construction a cylindrical body 5, provided with a tapering reduced and threaded extension 6, at its upper end, for attachment to the usual drill rod.

On the upper portion of the body 5 and at diametrically opposite points thereon are reamer rollers 77 rotatable on the pins 8, which have their ends anchored to the arms 9-9 in the manner clearly shown in Figure 2.

The lower extremity of the body 5 has its opposite side portions bevelled in converging relation toward the lower end of the body in the manner designated by the numeral 10. Upwardly from the lower extremity of the body the same is provided with a pair of enlargements 11-11 which extend from diametrically opposite points on the body and these enlargements are each provided with an upwardly bevelled surface 12. Each bevelled surface 10 and 12 of the body has a threaded opening therein to receive the threads 13 on an inclined stub shaft 14. The opposite end of each stub shaft protrudes beyond the surface of the body and is provided 1929. Seri a1No.'356,078.

Withthreads 15, disposed in an opposite direc tion to the threads 13. f f I v I 5 Each shaft is provided with longitudinally extending channels'16 extending inwardly from the outer ends thereof for receiving the tongues 17. on the bearing-plates 18. Each bearing plate 18 is provided with lugs 19 engageable in recesses in the body 5 so that when the bearing plates 18 are properlyassociated with the shaft 14 and the body 5, the 66 shafts 14 will be prevented from rotating.

, Each shaft rotatably carries a discj20 of the type havingaconvex-outer surface 21 and a plane surface 22 at its inner side for engagement against the bearing plates 18. Each disc 20 has a central pocket in its outer surface for receiving nuts 24 engaged over the outer ends of the shafts 14, so that no projections are formed on the bit which will interfere with the cutting action thereof.

From a consideration of the drawings it will be seen that upper and lower sets of cutting discs have been provided, the lower discs being disposed in downwardly converging relationship, the upper discs being disposed in upwardly converging relationship, said upper discs having their lower edges at substantially the level of the midpoint of the lower discs.

The body 5 is provided with a longitudinally extending bore 25, from which extends branch ducts 26, at its lower end through which water may be supplied for moistening the earth in advance of the cutting disc.

In the modified form of the invention illustrated in Figure 3 of the drawings, the body 5 terminates at its lower end in a pair of depending legs on the inner sides of which the lower set of the discs 20' are mounted for rotation, suitable trunnions being provided on 9 said legs for the lower discs.

While the foregoing specification has been worded in general terms, it is to be understood that various changes in the shape, size, and materials may be resorted to, without departing from the spirit and scope of the invention as claimed hereinafter.

Having described the invention, what is claimed as new is:

1. A bit of the character described comprising an elongated body, upper and lower sets of cutting discs, the upper discs'being disposed in upwardly converging angular relationship, the lower discs being disposed in downwardly converging angular relationship, said upper discs being positioned on said body with their lower edges at substantially the level of the mid-points of said lower discs.

2. A bit of the character described comprising an elongated body, upper and lower sets of cutting discs, the upper discs being disposed in upwardly converging angular relationship, lower discs being disposed in parallelism with each other, said upper discs being positioned on said body with their lower edges atsubstantially the level of the midpoints of said lower discs.

3. bitof the character described comprising an elongated body, upper and lower sets of cutting discs, the upper discs being disposed in upwardly converging angular relation, the lower discs being disposed in oblique angular relationship with respect to the upper discs, said upper discs being positioned on said body with their lower cutting edges at substantially the level of the mid-points of said lower discs.

In testimony whereof I aflix my signature. JOHN. W. MARTIN. 

